Steam-engine



(No Model.)

, 2 sheets-sheet 1'. G.' E. DOW. STEAM ENGINE.

Eaten-ted MM. 1, 1887.

/l/llllll- O A M7 E lllllllllll Witnesses.'

N. PETERS. Pholwlilhognpmr wnhngxon. D, C.

2 Sheets-Sheet 2.

(No-Model.)4

G. E. DOW.

STEAM ENGINE.'

Inl/@wf Patented Mar. 1, 1887..

UNITED STATES PATENT OFFICE.

GEORGE E. DOW, OF ROCHESTER, NEW YORK.

STEAM-ENGINE.V

SPECIFICATION forming part of Letters Patent No. 358,435, dated March 1, 1887.

Application filed December 1G, 1885. Serial No4 ll.

To all whom t may concern.-

Be it known that I, GEORGE E Dow, a citizen of the United States, residing at Rochester,

in thecounty of Monroe and State of New I York, have invented a new and useful ,Steam- Engine, of which the following is a specification.

My invention has reference to an engine in which two pistons, attached rigidly to opposite ends of a connecting-rod, are arranged to reciprocate in cylinders subject to the pressure of steam against their outer faces; and it consists in an improved construction ot' a tubular reciprocating valve adapted to be rotated on its axis to reverse the motion of the engine, and in various details in the construction and arrangement of the several parts whereby a durable, economical, and compact engine is secured.

Referring to the accompanying drawings, Figure l represents a horizontal longitudinal central section through my engine. Fig. 2 is a side elevation, partially in section, ot the main valve and the steam-chest in which it is mounted. Fig. 3 is a side elevation of the engine.

Referring to the drawings, in constructing my engine I first provide a body consisting of two cylinders, A, closed at their outer ends and attached at their inner ends to an intermediate body or chamber, B, into which they open, as shown. I prefer to form this entire body in one piece of cast metal, as shown in the drawings, but it is manifest that the cylinders may be constructed separately and bolted or otherwise secured to opposite ends of the intermediate body or chamber. In each ofthe cylinders I mount a piston, G, and attach these two pistons rigidly to opposite ends of the connecting-rod D. Through a stuffingboX at one vside of the chamber B, I insert the main engine-shaft G, provided at its=in ner end, within the chamber B, with a crank or crankwheel, F, which is connected by a pitman, E, to one end of the rod D, as plainly shown in Fig. l, this arrangement causing the reciprocating movements of the pistons to effect the rotation of the crank and shaft.

'As a means of permitting the escape of-the exhaust-steam at the end of the stroke, longitudinal ports or groovest are formed at the inner ends of the cylinders, so that as each piston completes its inward stroke it will pass section.

(No model.)

over and uncover the inner ends of the grooves, whereupon the steam will escape from the cylinder past the' periphery of the pistons through the `grooves into the chamber B.

To the side or top of the body I secure a valve-chest, H, of cylindrical form in cross- This chest extends the entire length of the engine and communicates near its ropposite ends, by ports t a', with the outer ends of the respective cylinders. At one end the chest H is connected to the steam-supply pipe J, from which the live steam passes into the chest H, and thence by the valve, to'be presently described, through the ports c a into the i two cylinders alternately, thus driving the pistons to and fro. Y

I represents the main valve, construct-ed of a tubular form and mounted Within the valvechest H in suoli manner that it may reciprocate and also revolve, for purposes of reversal, upon its own axis. Ports b and b are formed through this valve on one side in such position that they register alternately with the ports a a', in order to permit the live steam to pass into the cylinders. On the opposite sidev the valve is provided with similar ports,

c and c', which may be brought into action by giving the valve a half-revolution about its longitudinal axis. These second ports are in such position wit-l1 reference to the ports b and b that when brought into action they will reverse the course of the steam through the ports a and c', and thus reverse the motion of the engine.

At each end the valve is provided in its periphery with exhaust-ports, each consisting 'of a longitudinal groove, g, having lateral branches h and h', as plainly shown in Fig. 2. These ports are for the purposeof permitting the escape of such steam as may fail to escape through the ports t. Atits two ends the valve is fitted closely within the surrounding steamchest, but at about the middle portion of the valve there is an annular space, k, between the periphery of the valve and the interior of the chest, formed in the present instance by enlarging the internal opening of the chest. This annular space 'communicates on one side through a port, m, with the central chamber, B, of the body, and also communicates with the exhaust-pipe n, leading from the engine.

As the valve is moved to and fro longitudinally the exhaust-ports at the opposite ends ICO are brought into action alternately. As each port is called into action its longitudinal portion g communicates with the steam-space 7c, and lat the saine time one of its lateral branches, h or h', (according to the direction in which the engine is running,) communicates with the port aor a', leadinginto the adjacent cylinder, as shown in the right hand of Fig. 2, so that the steam escapes through the cylinder-port into the lateral branch of the exhaust-port, and thence through the longitudinal portion of said port into space k, and nally through the port m into the crank-chamber B.

To effect the longitudinal motion of the valve I extend a rod or spindle, o, from its end through a stuffing-box to the exterior and connect said spindle by a swiveling connection, J',

to a pitman, K', actuated by an eccentric, L, on the main shaft.

To secure the reversal of the engine I make the valve rod or spindle of' angular form in cross-section and pass it through a corresponding guide, p, provided with a hand-lever and mounted in a stationary standard or other support, q. By turning this handle Iam not only enabled to reverse the motion of the engine, but to control the amount of live steam entering the cylinder.

The chamber or, body B, through which the steam escapes and in which the crank and its connections are tightly inelosed, is provided at its top Witha large anged opening, covered by a removable plate, P, the removalofwhich will afford access to all the internal parts.

The construction of my engine is such that it' a lubricator be attached to the steam-supply pipe the oil entering saidpipe will, in regular course, pass to the bearing-surfaces ol' the valve and the pistons, and will, in its course, thoroughly lubricate the crank-connections.

To regulate the quantity of steam used by the engine a governor of any approved construction lnay be connected with the valvespindle to effect its rolling or rotating motion.

It is to be noted Athat in my engine the valve is of exceeding simplicity and that the steampressure is so applied that the valve will be operated with slight friction.

I am aware that two pistons have been attached to opposite ends o f a connecting-rod and arranged to work in separate cylinders, and also that tubular valves have been constructed in various forms; but I believe myself' to be the first to construct and arrange the ports in the manner shown in the drawingsand recited in the following claims.

I believe myself the first to provide a cylinder with two distinct ports for exhausting the steam from one and the same side ot' the piston, one port controlled by the piston and the other by an automatic valve, and it is maniftst that as regards this combination the valve may be of any ordinary construction.

Having thus described my invention,what I claim is-` 1. In a reversible steam-engine, the two cylinders and their connected pistons, in combination with the cylindrical valve-chest closed at one end and provided with a steam-admission pipe at the opposite end, the port leading from said chest to the chamber between the pistons, and the tubular valve having a central opening from one end to the other, said valve provided at each end with the two steaminlet ports extending therethrough and with an exhaust-slot having lateral branches, saidv valve having its ends fitted closelywithin the encircling-chest.

2. The tubular valve having the live-steam passage therethrough from end to end,the livesteam ports opening outward therethrough,

and the exhaust ports or grooves in its outer surface, in combination with mechanism, substantially as described, for imparting alongitudinal motion thereto, the spindle o, fixed to the valve and projecting externally, and the rotary guide P, through which the spindle passes, provided with a hand-lever, whereby the attendant may adjust the levers without stopping its motion.

3. In a reversible steam-engine, two cylinders closed at their outer ends and provided with stean1-ports,an intermediate closed chamber communicating direct-ly with the inner ends of both cylinders, two pistons mounted in the respective cylinders and connected by an intermediate rod, a cylindrical valve-chest communicating midway of its length by the port m with said chamber, and the rotary reciprocating valve I, having its two ends fitted closely within the surrounding chest and provided with induction and eduction ports, as described, and its middle surrounded by a chamber, h, 'communicating directly with the chamber between the cylinders.

4. The cylindrical valve-chest with a steamadmission opening at one end and two ports, c a', at its side, in combination with the tubular valve fitted closely at its ends within the chest and surrounded at the middle by an eX- haust-steam space, said valve provided at each end with inlet-ports therethrough and with exhaust-ports in its outer surface, the exhaustports adapted to connect the ports c a.' with the exhaust-steam space. y

5. In a steam engine, the two cylinders closed at their outer ends and opening at their inner ends directly into the intermediate crankchamber, each cylinder provided at the outer end with a steam-port, c, and at the inner end with a grooved port, t, opening directly to the crank-chamber, in combination with the connected pistons arranged to uncover the respective ports t and the valve, substantially as described, delivering steam alternately into and out of the cylinders through the outer ports, a.

GEO. E. DOW.

Witnesses:

WM. S. REDFIELD, W. W. LAMB.

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